67871561 has 4 divisors (see below), whose sum is σ = 68246724. Its totient is φ = 67496400.

The previous prime is 67871549. The next prime is 67871563. The reversal of 67871561 is 16517876.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11155600 + 56715961 = 3340^2 + 7531^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-67871561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (67871563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 187310 + ... + 187671.

It is an arithmetic number, because the mean of its divisors is an integer number (17061681).

Almost surely, 2^67871561 is an apocalyptic number.

It is an amenable number.

67871561 is a deficient number, since it is larger than the sum of its proper divisors (375163).

67871561 is a wasteful number, since it uses less digits than its factorization.

67871561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 375162.

The product of its digits is 70560, while the sum is 41.

The square root of 67871561 is about 8238.4198120756. The cubic root of 67871561 is about 407.9083660193.

The spelling of 67871561 in words is "sixty-seven million, eight hundred seventy-one thousand, five hundred sixty-one".